Program Information
Investigation of a Novel Radiochromic Film Material for Radiotherapy Applications
M Abdel Gawad1*, A Eldib1,2 , S Lotfy3 , O Desouky4 , (1)Biophysics branch, physics department, AlAzhar University, Cairo, Egypt, (2) Fox Chase Cancer Center, Philadelphia, PA, USA (3) Polymer Chemistry Department, National Center for Radiation Research and Te, Cairo, Egypt, (4) National Center for Radiation Research and Technology, Cairo, Egypt
Presentations
SU-I-GPD-T-458 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: Gafchromic and Radiochromic films are the most used films in radiotherapy measurements. Another type of film that is still under research is the Polyvinyl Alcohol (PVA) films. After PVA casting and drying, a new film of PVA with small thickness can be used as a film dosimeter. In the current work, we investigate modifying the composition of PVA dosimeter by adding radio-sensitive component and study its feasibility as a film dosimeter.
Methods: We used PVA mixed with ferrous as a radio-sensitive element and an organic dye as color change indicator. The new dosimeter was flattened using two slabs of glass above and under the batch. After preparation the new film was cut to small samples for irradiation. The samples were irradiated in solid water phantom and a thick layer of Bolus was used as a buildup. Elekta precise© clinical treatment linear accelerator machine was used to irradiate the samples with 6MV beam. A spectrophotometer system was used for measuring the color changes (the absorbance) before and after irradiation and then we calculated the net absorbance.
Results: Our measurements were done in the range from 1 to 20Gy. The net absorbance showed a logarithmic dependence on the delivered dose in the range of 5 to 20Gy. The chromatic changes at the low dose suggest the potential application of the film in light field coincidence quality assurance procedures. These films will not require chemical processing sharing the advantage of other radiochromic films. In addition it is expected to be cost effective. Its response at the dose higher than 5Gy makes it suitable for dosimeteric verifications of steretactic radiosurgery/radiotherapy treatment plans and can be used be used for patient specific quality assurance for cyberknife plans.
Conclusion: The new film has shown promising results and could have potential applications in radiotherapy quality assurance
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